An atheist and agnostic association filed a complaint against the Tennessee magistrate who refused to allow a couple to name their baby "Messiah."

The Freedom From Religion Foundation accused child support Magistrate Lu Ann Ballew of violating the state's code of judicial conduct.

The baby's parents were in court because they couldn't agree on the baby's last name, but what caught the judge's attention was the baby's first name.

"The word Messiah is a title and it's a title that has only been earned by one person, and that one person is Jesus Christ," Ballew said.

Ballew ordered the baby's first name to be changed to "Martin" and keep the father's last name.

The parents said they will appeal the ruling. In the meantime, they'll keep calling their baby "Messiah."

"I never intended on that -- naming my son Messiah because it means God," The baby's mother, Jaleesa Martin, told WBIR-TV. "And I didn't think a judge could make me change my baby's name because of her religious beliefs."

Critics question whether a judge should be able to change a baby's name.

"Bottom line, parents, not the government, have the right to select a name for their child," Hedy Weinberg, executive director of American Civil Liberties Union -Tennessee, told ABC News. "While the judge has a right to her religious beliefs, she cannot impose her faith on those who appear in her courtroom.

"Tennessee law is pretty clear that you can change your name to whatever you want, as long as it does not harm someone else or you haven't been convicted of a few specific crimes. But it doesn't even apply to [the judge]," she said.